Bellows air pump



Dec. 4, 1962 E. LANDENBERGER BELLOWS AIR PUMP 2 Sheets-Sheet 1 FiledMarch 1'7, 1961 INVENTOR. 06517 1 Alt 0571911 650 MdW Dec. 4, 1962 E.LANDENBERGER BELLOWS AIR PUMP Filed March 17, 1961 2 Sheets-Sheet 2Fig.4

INVENTOR.

l/6E/V l ANDE/VBERGIFR A rrap/vsy 3,066,853 Patented Dec. 4, 196.2

3,066,853 BELLOWS AIR PUMP Eugen Landenberger, Gallen, Witzerland,assignor to Walter Anderes, St. Gallen, Switzerland Filed Mar. 17, 1961,Ser. N0. 96,455 Claims priority, application Switzerland Mar. 28, 1960 9Claims. (Cl. 230---16tl) The present invention relates to an air pumpwith a cylindrical bellows, and it is the primary object of theinvention to provide a pump of this type which is easily transportable,adapted to be driven by a motor, and to be operated continuously,inexpensive in production and maintenance, and especially suitable foruse in sports, camping, fishing, or for similar purposes.

For blowing up air mattresses, pneumatic boats, air pillows, swimmingrings, and the like, as well as camping equipment of various kinds, itis conventional to use air pumps with hemispherical or cylindricalbellows which are operated by foot. Although this is a tiresomeoperation even with smaller articles, it requires a very great effort aswell as considerable time to pump up a larger article by foot, forexample, a pneumatic boat. These disadvantages may be avoided by meansof a bellows pump according to the invention which is adapted to bedriven by a small electric motor which may, for example, be connected tothe starter battery of an automobile so that the pump may then even beused in a continuous operation, for example, for aerating tanks fortrout and other kinds of fish which, after being caught, will diequickly unless they are kept in tanks in which the water is frequentlyor continuously aerated.

An essential feature of the present invention consists in mounting thebellows of the air pump at both ends in cylinder covers which areprovided with valves and one of which is adapted to reciprocate byturning back and forth about its own axis at an angle of, for example,100, while the same or the other cover is resiliently movable in theaxial direction.

The reciprocating cylinder cover of the bellows is preferably mounted ona crossbar which is secured to the driveshaft of an eccentric gear unitwhich is driven by an electric motor to produce the desiredreciprocating movement.

Since the bellows is shortened when being twisted, either thereciprocating cylinder cover is supported on its mounting bracket bymeans of spring-loaded sliding pins or the other cylinder cover ismounted on a bifurcated member which is adapted to pivot about ahorizontal axis against the action of a spring.

The pump according to the invention is preferably mounted on ahorizontal base which is provided with lateral extensions for increasingthe stability of the base. In order to render the pump more easilyportable the space required by it may be reduced by making the base oftwo parts and by fitting one part in such a manner upon the other thatthe lateral extensions of the two parts will be directly adjacent toeach other.

Furthermore, at least one cylinder cover is adapted to be disconnectedfrom its support, for example, by means of a screw connection, in orderto permit the bellows to be easily exchanged.

The above-mentioned and further objects, features and advantages of thepresent invention will become more clearly apparent from the followingdetailed description thereof, particularly when the same is read withreference to the accompanying drawings, in which FIGURE 1 shows a sideview of an air pump according to the invention in the starting position;

FIGURE 2 shows a side view of the pump according to FIGURE 1 in aposition in which the rear cylinder cover has been turned about its axisat an angle of approximately FIGURE 3 shows a top view of the pumpaccording to FIGURE 1;

FIGURE 4 shows a side view of a modification of the pump according tothe invention;

FIGURE 5 shows a side view of the pump according to FIGURES l and 3 inthe position for transport or storage; while FIGURE 6 shows adiagrammatic illustration of a gear system for producing thereciprocating movements of the right cylinder cover.

Referring first to FIGURES 1 to 3 of the drawings, the pump according tothe invention comprises a normally cylindrical bellows l which isremovably clamped at both ends in cylinder covers 3 and 4 of sheet metalor plastic, for example, by means of a spring ring which is pressed intoeach cylinder cover and connected to the respective end of the bellows.Cover 3 is provided with an air inlet opening 5 and an inlet valve. 6which may in the simplest form consist of a rubber disk which is rivetedonly at one side to the cover. Cover 4 has an air outlet opening 7containing a check valve 8 and a nipple 9 for attaching a flexible tube10. Check valve 8 may also be of a design as simple as the suction valve6 and may also consist of a rubber disk which is secured only on oneside. In this case, cover 4 is preferably provided with an intermediatepartition 45 to which the rubber disk which serves as a check valve 8 issecured at the side facing toward the outside of cover 4.

Cover 3 is provided with two diametrically opposite projecting pins 11and 12 which engage into a pair of pins 13 and 14 on a crossbar 15 inwhich these pins 13 and 14 are removably secured by setscrews 16.Crossbar 15 is rigidly secured to a drive shaft 17 which may be turnedback and forth by a motor 18 about an angle of approximately Motor 18 isfor this purpose provided with an eccentric gear unit 19 which isdiagrammatically illustrated in FIGURE 6. By means of severalintermediate gears, the motor shaft 20 drives a gear 21 which has a pin22 in an eccentric position thereon. A gear rack 23 which is slidable ina guide member 24 is rotatably mounted at one end on pin 22 and thusreciprocated thereby. Rack 23 engages with a pinion 25 on drive shaft 17of the pump which is thus continuously turned back and forth.

Motor 18 and gear unit 19 thereon are mounted on drive shaft 17 which bymeans of a bearing 26 is mounted on a bearing bracket 27 on a base 28which carries the pump.

For camping purposes, it is advisable to use a 6 or 12 volt motor whichmay be connected to the starter battery of an automobile by means of acable 29. Motor 18 may also be provided with a switch 30 for easilystarting and stopping the same.

As evident from the drawings, the pumping effect is produced byalternately lengthening and shortening the size of the chamber inbellows 1 by turning the end of the bellows which faces toward motor 18by means of crossbar 15 back and forth about an angle of approximately100 and by thus twisting the bellows. Since by this twisting movement,the length of the bellows is reduced, one of the two cylinder covers 3or 4 of bellows 1 must be resiliently movable in. the axial direction ofthe bellows. This is done according to the embodiment as shown inFIGURES 1 to 3 in such a manner that the cylinder cover 4 at the leftside of the bellows is mounted by a pair of pins 31 within a bifurcatedsupporting member 32 which is pivotably mounted at 33 on base 28. A pairof tension springs 34 tend to maintain bellows 1 in the extendedposition in which it has a cylindrical shape and in which the c eesesbifurcated supporting member 32 extends substantially perpendicular. Inthe operation of the pump bellows 1 will be shortened when being twisteddue to the fact that the left cover 4 will yield in the axial directionof the bellows when the bifurcated member 32v pivots to the position asshown in FIGURE 2.

FIGURE 4 illustrates another embodiment of the invention according towhich the cylinder cover 3 at the driving side of the pump is connectedto crossbar by means of pins 36 which are slidable therein against theaction of springs 37. When in the operation of the pump crossbar 15 isturned to twist bellows 1, the latter will be shortened due to the factthat pins 36 on cover 3 will slide in crossbar 15- toward the left ofFIGURE 4 against the action of springs 37.

Base 28 of the pump consists of two flat iron bars 38 and 39 of asubstantially equal length which in the operative position according toFIGURE 1 are connected to each other by pins 4t For increasing thestability of the base, each bar 38 and 39 is provided with a crossbar 41or 42, respectively. In the shipping position of the pump, as shown inFIGURE 5, the two longitudinal bars 38 and 39 are placed upon each otherin a position in which the connecting pins 40 on bar 38 engage intobores 43 in bar 39 at both sides of hearing bracket 27, and in which thetwo crossbars 41 and 42 lie directly adjacent to each other. The lengthof the pump will thus be considerably reduced, permitting it to bestored and transported very easily and within a small space.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments, but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim 1. An air pumpcomprising a substantially cylindrical bellows of flexible material, apair of covers secured to each end of said bellows respectively, an airinlet valve in one of said covers, an air outlet valve in the other ofsaid covers, a pump base, means for nonrotatably mounting one of saidcovers on said base, means for rotatably mounting the other cover onsaid base, eccentric gear means for rotating said other cover back andforth about its axis, so as to twist and unwtist said bellows, a motoroperably connected to said gear means for actuating said eccentric gearmeans, support means enabling one of said covers to move in an axialdirection from a predetermined starting position toward the other coverduring said twisting movement of said bellows and spring means engagingwith said axially movable cover for returning it to the startingposition during the untwisting movement of said bellows.

2. An air pump comprising a pump base, a bifurcated supporting memberpivotably secured to said base, a fixed support member mounted on saidbase and spaced from said bifurcated member, a substantially cylindricalbellows of flexible material, a pair of covers secured to each end ofsaid bellows respectively, one of said covers being pivotably mounted insaid bifurcated member and having an air outlet valve and being axiallydisplaceable from a predetermined starting position toward the other ofsaid covers, a crossbar secured to said other cover, said other coverbeing provided with an inlet valve, a drive shaft secured tosaid'crossbar, an electric motor provided with an eccentric gear unitmounted on said fixed support, said eccentric gear unit being connectedto said drive shaft for repeatedly turning said drive shaft back andforth about its axis so as to twist and untwist said bellows during themotors operation and a spring having one end secured to said bifurcatedmember and another end to said base for biasing said axiallydisplaceable cover to said starting position during the untwistingmovement of said bellows.

3. An air pump comprising a pump base, a pair of spaced supportingmembers fixedly secured to said base, one of said members beingbifurcated, a substantially cylindrical bellows of flexible material, apair of covers secured to each end of said bellows respectively, one ofsaid covers being mounted in said bifurcated member, the other of saidcovers being provided on its periphery with a pair of diametricallyopposite projections, a crossbar disposed adjacent said other cover, apair of pins slidably extending through the respective ends of saidcrossbar, one end of each of said pins engaging with said projections, apair of coil springs mounted between the other ends of said pins andsaid crossbar for biasing said other cover adjacent said crossbar, saidother cover being axially displaceable from a predetermined startingposition toward said one cover, a drive shaft secured to said crossbar,an electric motor provided with an eccentric gear unit mounted on theother of said supporting members, said eccentric gear unit beingconnected to said drive shaft for repeatedly turning said drive shaftback and forth about its axis so as to twist and untwist said bellowsduring the motors operation, said springs urging said other axiallydisplaceable cover to said starting position during the untwistingmovement of said bellows.

4. An air pump as defined in claim 1, in which said motor and saideccentric gear means are adapted to turn said rotatable cover back andforth about an angle of approximately 5. An air pump as defined in claim4, further comprising an intermediate member, means for connecting saidrotatable cover to said intermediate member so as to be nonrotatable butslidable in the axial direction of said bellows relative to each other,said spring means acting upon said rotatable cover and said intermediatemember.

6. An air pump as defined in claim 5, further comprising an elongatedbase having crossbars, said pump being mounted on said base.

7. An air pump as defined in claim 6, in which each of said parts ofsaid base comprises an elongated member and a cross-bar secured to oneend thereof, said elongated members being superimposed upon each other,said crossbars being disposed Within the same plane, said crossbarsbeing spaced from each other in said extended position and closelyadjacent to each other in said contracted position of said base.

8. An air pump as defined in claim 7, further comprising means forremovably connecting at least one of said covers to its mounting means.

9. An air pump as defined in claim 6, in which said base comprises twoparts, one of said parts being pro vided with a pair of upwardlyextending pins, the other of said parts having at least two pairs ofbores at its respective ends, each of said pair of bores being adaptedto interchangeably receive said pins for connecting said parts to eachother to set up said pump in an operative or nonoperative position.

References Cited in the file of this patent UNITED STATES PATENTS BowerOct. 22, 1957

